During disassembly of a BWR, the steam outlet nozzles must be plugged to allow maintenance and testing of the main steam isolation valves in parallel with reactor refueling and servicing operations. The steam line plugs are used to seal the steam lines to prevent the flow of water from the reactor cavity during servicing of the safety valves, relief valves and main steam isolation valves.
Historically, plug installation has been performed using an overhead crane and service poles manipulated by hand. This conventional operation is attended by problems. First, this current method of installing the plugs requires that personnel be located in the reactor cavity to position and maneuver the steam line plugs as they are being lowered by the overhead crane. Second, the current method of installing the plug requires that personnel push the plug into the steam outlet nozzle from the opposite side of the reactor vessel using a pole. Third, the steam line plug installation envelope should allow for unobstructed removal of the steam separator. Conventional installation tools interfere with or obstruct the removal of the separator and must be disengaged from the plug and removed after the plug has been installed.